System and method for harmonic interference avoidance in carrier recovery for digital demodulation
CA 2279850 A1 · Owner: Scientific-Atlanta, Inc. · Inventors: Hanna, Kenneth M.; Coman, Ion
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to an improved demodulator for locking onto and tracking a carrier. Harmonic frequencies are occasionally generated by demodulation circuitry. When this occurs the harmonic frequencies can , interfere with the demodulator's locking and tracking functions especially if , the harmonic frequencies are near a down converted carrier's frequency. A system and method are disclosed which provides an offset to a frequency synthesizer (107) whose output frequency (F1 F2) is used to down convert , (104) the carrier. The offset alters the frequency of the down converted carrier so as to shift it away from the interfering harmonics. In this regard the demodulator is …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed January 15, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 15, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 15, 2020.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.